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Beyond its design, the way your product or part is molded has the greatest impact on its cost and functionality. Great ideas can be derailed if they are pursued in the wrong direction. As a result, it is prudent to consider your options early in the design process. How do you tell when liquid molding is finished and injection molding is about to begin?

Differences Between Thermoplastic and Thermoset
One of the first questions to ask, though it is not always the most important, is: How many pieces do I need to make? As a rule, high volume necessitates rapid production, which is one of the primary advantages of injection molding. Thermoplastic molds, on the other hand, are expensive to produce, and production runs in the thousands or millions are typically required to recoup the cost of the mold. Liquid molding can be accomplished using a variety of tooling techniques such as plastic or composite molds or soft rubber molds, which can significantly reduce upfront costs while still producing high-quality plastic parts for both prototyping and low-volume production.(1,000-5,000 pieces)

The three major families of thermoset resins are polyurethanes, epoxies, and silicones. Polyurethanes are the most common type of thermoset resin. Polyurethanes are the most widely used of these materials, and they are available in both elastomeric and rigid formulations. Epoxies are frequently used in high-temperature and corrosion-resistant applications, but their high cross-link density results in a tendency for brittleness. When continuous flexibility over a wide temperature range is required, silicones should be considered. Their natural self-releasing (non-stick) characteristics can be used to a molder's advantage in certain situations.

The Advantages of Liquid Molding Thermoplastics are available in pellet or sheet form, and they must be melted and formed with the help of specialized molding equipment.
One major advantage of using these materials is that they can be re-melted and re-formed multiple times, as opposed to thermosets, which are chemically inert once they have been cured.

Another significant advantage of liquid molding over conventional injection molding is that the process allows for significantly more design flexibility. Because the casting process does not require the use of high temperatures and pressures to initially melt the material in order for it to flow evenly into the mold, the designer is not restricted to maintaining uniform part geometry during the design process.

Liquid molding is particularly well suited to the production of highly complex parts in small batches, and it may always be the preferred method in the early stages of production. Besides medical and surgical equipment, scientific instrumentation, and electronics, to name a few industries where it can be advantageous over injection molding. When part volumes exceed a few thousand, however, injection molding is almost always the most cost-effective method of producing the parts.